The invention relates to a process and apparatus for determining quantities relevant to enthalpy of a gaseous medium, such as degree of moisture in gases, vapor humidity or enthalpy of dry steam.
A similar process has been described in German Pat. No. 2,235,853. With this known process the gas flow to be measured is cooled below the dew point by means of a continuously operating countercurrent cooling device. The heat exchange with the cooling device is measured and the temperature of the gas flow is determined prior to and after the cooling operation and the moisture contents is found via the heat balance equation. The apparatus used in this process is provided with a pump which sucks the gas flow through the countercurrent cooler. A second pump which is operated together with the first pump by a motor drives the flow of the cooling agent through the cooling device. Temperature sensors are provided to measure the temperature, the inlet and the outlet temperature for the gas and the inlet and outlet temperature of the cooling water. The data thus obtained are passed into a computer where the results are produced by virtue of the heat balance equation.
A shortcoming of this process and device is that in order to measure the heat released to the system for changing the physical condition, that is the cooling device, it is always necessary to maintain a flow of cooling medium. Any device of this kind can therefore be only used as a stationary apparatus.
An object of the present invention is to simplify prior art devices of this kind and to permit a broader use thereof.